In December 1991, representatives of 12 European nations met in the small Dutch town of Maastricht to negotiate one of Europe's most significant documents.

The Treaty on European Union -- or "Maastricht Treaty" -- took the European Community and made it into the European Union. Most importantly, it defined the terms and conditions for the introduction of the single currency, the euro, and, thus, economic and monetary union.

In addition, the treaty mapped out other forms of cooperation between the member states. It defined a common foreign and security policy. The countries also stipulated combined efforts in justice and home affairs, for example law enforcement and immigration. By adding these two areas to the existing Community, the so-called "three pillars" of the Union were established.

A difficult birth

But while politicians patted themselves on the back for working out the Maastricht Treaty, some Europeans were anything but pleased.

Many member states had difficulties even ratifying the Treaty. The Danish completely rejected it. Only after several alterations did it scrape through. France also gave Maastricht a less than enthusiastic response. Its referendum approved the Treaty only by a tiny margin.

In Germany, it was even sent to the constitutional court to determine whether it was compatible with the constitution. The court in the end voted in favor of the Treaty.

The Treaty was finally signed at Maastricht on February 7, 1992 and came into effect on November 1, 1993. It amends the Treaty of Rome, which established the European Economic Community in 1957.

Political unity still in the distance

A decade later, Europe consists of 25 existing and future member states. The central component of Maastricht -- economic and monetary union -- was completed with the introduction of the euro on January 1, 2002.

But the EU is still working on its political unity. In June, a draft constitution was painfully born after 16 months of hard bargaining by a forum of EU ministers and parliamentarians led by former French president Valerie Giscard d'Estaing.

It is designed to streamline decision-making within the EU after it expands from 15 to 25 members next May. Yet many smaller member states are concerned about the future distribution of power within the EU and are requesting changes. Only when these problems have been ironed out will the political spirit of Maastricht finally be fulfilled.

The 12 nations which signed the Maastricht Treaty were Belgium, Denmark, France, Germany, Great Britain, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal and Spain. It has been amended to a degree by later treaties.